Answer:
x=7
Step-by-step explanation:
3/x-4=7/x
Using cross products
3 * x = 7 (x-4)
Distribute
3x = 7x -28
Subtract 7x from each side
3x-7x = 7x-7x-28
-4x = -28
Divide each side by -4
-4x/-4 = -28/-4
x = 7